You can create a data map that defines one or more records for a source or target database or data file. In the simplest case, a data map contains one record and one table that is derived from the record. The table provides a relational view of the data.
You can create a data map with multiple records by importing a copybook that defines multiple records or by specifying Record ID Values for a field. A data map with multiple records is referred to as a multiple-record data map.
Use multiple-record data maps in the following cases:
Each segment in an IMS source has a different record definition.
For a sequential, flat file, or VSAM data source, you define different records based on the record ID values that you enter for a field in the Field Properties dialog box.
You need to distinguish redefined records that store field data sometimes as numeric data and sometimes as alphabetic data, depending on other information in the record.
When you create a data map for a sequential file or VSAM data source, you can define record properties that identify hierarchical relationships among the records or redefined records. PowerExchange and PowerCenter use this information to write multiple record types to VSAM or sequential targets while preserving the sequencing of the source data. For IMS unload data set sources, PowerExchange uses the segment information that you import from an IMS DBD into the multiple-record data map to write multiple record types to an IMS unload data set target.